Image forming apparatus having restricted USB socket

ABSTRACT

An image forming apparatus is provided with USB sockets on front and back sides, and includes a determining unit for determining whether or not a USB device inserted to a front side USB socket  184  is a function enhancement device, and a control unit making, when it is determined by the determining unit that a function enhancement device is inserted to the front side USB socket  184 , the USB device unusable and making, when it is determined that a USB device other than the function enhancement device is inserted, the USB device usable. Thus, it is possible to prevent a USB wireless LAN adapter or the like from being used constantly connected to the front side USB socket and thereby to reduce possibility of USB wireless LAN adapter of being damaged or removed.

TECHNICAL FIELD

The present invention relates to an image forming apparatus having a USB(Universal Serial Bus) port and, more specifically, to an image formingapparatus capable of preventing damage to or erroneous removal of aconnected function enhancement device such as a USB wireless LANadapter.

BACKGROUND ART

As one type of image processing apparatuses as electronic equipment, animage forming apparatus (typically a copy machine) for forming an imageon a sheet of recording paper has been introduced to many places ofbusiness (companies and offices). In such a place of business, it is acommon practice to have an image forming apparatus having a printerfunction or a copy function connected to a network and to share theapparatus by a plurality of users. An MFP (MultiFunction Peripheral) asone type of such image forming apparatuses has a plurality of basicoperational modes including a copy mode, a facsimile mode (hereinafterfacsimile will be also denoted as FAX), a network compatible printermode and a scanner mode.

The image forming apparatus has, for example, a NIC (Network InterfaceCard) as an interface for connection to the network. The NIC has aterminal, to which a communication cable such as a UTP (UnshieldedTwisted Pair) cable is connected, so that the image forming apparatus isconnected to the network. When connected to the network, the imageforming apparatus can realize the functions of receiving and printingimage data from a terminal such as a PC connected to the network,transmitting an image data obtained by scanning a document by attachingit to an electronic mail, or transferring the image data to a computerserver using FTP.

Recently, wireless network environment has come to be advanced, since iteliminates the necessity of hard-wiring and facilitates installment ofequipment. As a device for wireless connection, a compact USB adapterfor wireless LAN (hereinafter referred to as a USB wireless LAN adapter)in compliance with international standard such as IEEE802.11 series hasbeen widely used. When a USB wireless LAN adapter is mounted on anapparatus such as a PC, the PC becomes connectable to a router, anaccess point or the like by radio wave in the frequency band of, forexample, 2.4 GHz. Further, since Wi-Fi has made it possible to verifyinter-connectability among manufacturers of wireless LAN devices,wireless network connections are growing more popular.

By way of example, Japanese Patent Laying-Open No. 2011-82677(hereinafter referred to as '677 Reference) discloses a USB wireless LANadapter that changes the methods of communication (isochronous transferor bulk transfer) depending on the type of communication data (streamingdata or not) and on the situation of communication (isochronous transferis in progress or not).

A USB port of a PC or the like is used for connecting various peripheraldevices, in addition to the wireless LAN adapter. As a USB-connectableperipheral device, a USB memory is widely used. A USB memory is of largecapacity, small, light-weight, portable and easy-to-handle and,therefore, it is used for moving data of a large data size, such asimage data, to another device.

Image forming apparatuses having a number of USB ports have been known.In such an image forming apparatus, a USB wireless LAN adapter is usedin a constantly connected state, always connected to one USB port(always kept connected while the power of image forming apparatus isON), to enable wireless connection to the network. It is possible for auser to insert USB memory to another USB port of the image formingapparatus to input image data to be printed stored in the USB memory tothe image forming apparatus, or to store image data of a scanneddocument or the like in the USB memory to move to another device such asa PC.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

When a USB wireless LAN adapter is connected to a USB port on a frontside of an image forming apparatus, the USB wireless LAN adapter caneasily be pulled out and, hence, there is a possibility that the usererroneously pulls out the USB wireless LAN adapter, resulting indisconnection of communication. Further, since the user stands in frontof the image forming apparatus and operates the image forming apparatus,it is possible that the user's body touches or hits the USB wireless LANadapter and damages the USB wireless LAN adapter. Further, when a useror some other person passes in front of the image forming apparatus,he/she may inadvertently touch and damage the USB wireless LAN adapter.As described above, the conventional image forming apparatus has aproblem that a USB device such as a USB wireless LAN adapter isconnected to a USB port from which the inserted USB device can easily beremoved by a user, and used as it is.

In an apparatus having a plurality of USB ports as in the case of ageneral PC, a peripheral device can be used connected to any of the USBports. The same applies to the conventional image forming apparatushaving a plurality of USB ports. The above-described problem cannot besolved by the invention described in '677 Reference.

Therefore, an object of the present invention is to provide an imageforming apparatus capable of reducing the possibility of a USB-connectedfunction enhancement device such as a USB wireless LAN adapter beingdamaged by an external force and the possibility of such a device beingerroneously removed.

Means for Solving the Problems

The above-described object can be attained by the following.

Specifically, the object can be attained by the image forming apparatusin accordance with the present invention provided with a plurality ofUSB sockets. The image forming apparatus includes a determining unit fordetermining whether or not a USB device connected to a specific USBsocket of the plurality of USB sockets is a prescribed device; and acontrol unit for selectively executing a process of keeping unusable theUSB device determined to be the prescribed device, or a process ofmaking usable the USB device not determined to be the prescribed device,depending on a result of determination by the determining unit, and thespecific USB socket is arranged at a position allowing insertion andremoval of a USB device by a user operating the image forming apparatus.

Preferably, the prescribed device is a USB device for communication withexternal equipment.

More preferably, the image forming apparatus further includes anoperation unit receiving an instruction to the image forming apparatus;the specific USB socket is arranged on a front side of the image formingapparatus where the operation unit is arranged; and each of theplurality of USB sockets other than the specific USB socket is arrangedon a side other than the front side of the image forming apparatus.

More preferably, each of the plurality of USB sockets other than thespecific USB socket is arranged on a back side opposite to the frontside of the image forming apparatus.

Preferably, the determining unit determines whether or not the USBdevice connected to the specific USB socket is the prescribed device byobtaining class information of the USB device from the USB deviceconnected to the specific USB socket and determining whether or not theobtained class information is prescribed class information.

More preferably, the determining unit determines whether or not the USBdevice connected to said specific USB socket is the prescribed device byobtaining a vendor ID and a product ID of the USB device from the USBdevice connected to the specific USB socket and determining whether theobtained vendor ID and the obtained product ID are a prescribed vendorID and a prescribed product ID.

More preferably, the image forming apparatus further includes a displayunit for displaying information, and the process of the control unitkeeping unusable the USB device includes a process of displayinginformation that the USB device is unusable on the display unit.

Effects of the Invention

According to the present invention, if a USB device for communicationwith an external device is connected to that specific one of a pluralityof USB sockets (USB ports) provided on the image forming apparatusto/from which the user can easily insert/remove a USB device, the USBdevice is not made usable and, therefore, possibility of erroneousremoval during use or possibility of any damage can be reduced.

Since the USB socket positioned on the front side of image formingapparatus is the object of restriction, it is possible for the user toeasily use a USB memory or the like on the front side of image formingapparatus and, in addition, it is possible to prevent erroneousconnection of the specific USB device to the USB socket on the frontside.

Since the USB device of which use is restricted is determined usingdescriptor information (class ID, vendor ID and product ID) of known USBstandard, any USB device supplied from a manufacturer can be used as itis without any necessity of storing special information in the USBdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the image forming apparatus inaccordance with an embodiment of the present invention.

FIG. 2 is a perspective view showing a part of the back side of imageforming apparatus in accordance with an embodiment of the presentinvention.

FIG. 3 is a block diagram showing a schematic configuration of the imageforming apparatus in accordance with an embodiment of the presentinvention.

FIG. 4 is a flowchart representing a control structure of a programrestricting use of a USB device connected to a USB socket, in the imageforming apparatus in accordance with an embodiment of the presentinvention.

FIG. 5 is a perspective view showing a USB device inserted to a frontside USB socket of the image forming apparatus in accordance with anembodiment of the present invention.

FIG. 6 is a screen image showing an example of a message displayed onthe image forming apparatus.

FIG. 7 is a screen image showing an example of a message displayed onthe image forming apparatus.

FIG. 8 shows examples of class ID of USB descriptor.

FIG. 9 is a perspective view showing an image forming apparatus having aUSB socket on a side surface.

DESCRIPTION OF EMBODIMENTS

In the embodiment described in the following, the same components aredenoted by the same reference numbers. Their names and functions arealso the same. Therefore, detailed description thereof will not berepeated.

Referring to FIGS. 1 and 2, an image forming apparatus 100 in accordancewith an embodiment of the present invention forms a multi-color orsingle-color image on prescribed recording paper in accordance withimage data generated by reading a document. Image forming apparatus 100includes a body 110 and an automatic document feeder 120.

On an upper portion (inside) of body 110, an image reading unit 140 isarranged. Image reading unit 140 scans a document fed by automaticdocument feeder 120 and generates image data. At an upper portion ofbody 110, an operation unit 160 is arranged. Image forming apparatus 100executes a process in accordance with an instruction input throughoperation unit 160. At a lower portion of body 110, a paper feed unit156 for holding sheets of recording paper for forming images isarranged. Image forming apparatus draws out a sheet of recording paperfrom paper feed unit 156, forms an image on the surface of the sheet,and discharges the sheet to an in-barrel type paper discharge tray 170.

Body 110 has a front side USB socket 184 and a back side USB socket 186.Front side USB socket 184 is arranged on the front side, which hasoperation unit 160 thereon and faces the user operating image formingapparatus 100. Back side USB socket 186 is arranged on the back sideopposite to the front side. Specifically, back side USB socket 186 isarranged on the back side surface near a right side surface 112 of body110, as shown in FIG. 2. In FIGS. 1 and 2, USB devices to be inserted tofront side USB socket 184 and back side USB socket 186 are shown bydotted lines.

Referring to FIG. 3, image forming apparatus 100 includes a control unit(hereinafter referred to as CPU) 130 for overall control of imageforming apparatus 100, an ROM (Read Only Memory) 132 for storingprograms and the like, an RAM (Random Access Memory) 134 as a volatilestorage device, an HDD (Hard Disk Drive) 136 as a non-volatile storagedevice retaining data even when power is turned off, and a bus 142. ROM132 stores programs and data necessary for controlling operations ofimage forming apparatus 100.

CPU 130, ROM 132, RAM 134 and HDD 136 are connected to bus 142. Data(including control information) are exchanged between each of theseunits through bus 142. CPU 130 reads a program from ROM 132 to RAM 134through bus 142, and executes the program using part of RAM 134 as awork area. Specifically, CPU 130 controls various units forming imageforming apparatus 100 in accordance with a program stored in ROM 132 andrealizes various functions of image forming apparatus 100.

Image forming apparatus 100 includes, in addition to automatic documentfeeder 120, image reading unit 140, paper feed unit 156, operation unit160, in-barrel type paper discharge tray 170, front side USB socket 184and back side USB socket 186, an image forming unit 150, an imageprocessing unit 152, an image memory 154, a USB host controller 180 anda USB hub 182. These components (except for USB hub 182) are alsoconnected to bus 142. Though not shown, similar to a common imageforming apparatus, image forming apparatus 100 has an NIC for connectionto a network using a communication cable, a FAX communication modem orthe like.

Operation unit 160 receives inputs such as an instruction to imageforming apparatus 100 from a user. Operation unit 160 includes anoperation panel 162 and an operation key portion (an area of operationunit 160 other than operation panel 162). Operation panel 162 includes adisplay panel implemented, for example, by a liquid crystal panel, and atouch-panel arranged on the display panel, for detecting a touchedposition. In order to operate image forming apparatus 100, soft keys aredisplayed on the display panel, and on the operation key portion, hardkeys are arranged. CPU 130 monitors user's operation on these keys. Theuser can press or touch these keys to input an instruction of imageformation, settings of image formation conditions or the like to imageforming apparatus 100. Selection of a key displayed on the display panelcan be done by touching the corresponding portion of the touch-panelsuperposed on the display panel.

When the user operates operation unit 160 and thereby instructsformation of an image, image reading unit 140 reads a document andgenerates image data, and the image data is temporarily stored in imagememory 154. Image processing unit 152 executes various image processingoperations on the image data stored in image memory 154. The image datais stored in HDD 136 as needed.

Paper feed unit 156 includes a paper feed cassette and holds sheets ofrecording paper for forming images. Image forming unit 150 includes aphotoreceptor drum, a charger, an optical scanning device, a developer,a transfer roller, a fixing unit and the like, and forms image data readfrom image memory 154 or from HDD 136 on a sheet of recording paper fedfrom paper feed unit 156.

USB host controller 180, USB hub 182, front side USB socket 184 and backside USB socket 186 are connected in a known USB connection topology(multi-star topology). USB host controller 180 also serves as a root hubof the highest level. Front side USB socket 184 and back side USB socket186 are both sockets to which a known series A plug is connected.

In the following, a program for restricting use of a USB deviceconnected to the USB socket, executed in image forming apparatus 100will be described with reference to FIG. 4. Information (port number)for specifying the USB socket, the use of USB device inserted to whichis to be restricted, and information (information of USB descriptor, aswill be described later) for specifying the USB device of which use isto be restricted, are stored in advance in HDD 136. Here, “use of USBdevice . . . restricted” and “USB device of which use is to berestricted” mean the possibility that image forming apparatus 100 doesnot load a device driver (software program of lower level, necessary forthe OS (Operating System) to control hardware) corresponding to the USBdevice, so that the USB device is kept in a non-usable state.

In the following description, it is assumed that when a USB wireless LANadapter is inserted to front side USB socket 184, the USB wireless LANadapter is not set to a usable state, or it is kept unusable, while theuse of any USB device is not restricted when it is inserted to back sideUSB socket 186. Further, it is assumed that when a USB device other thanthe USB wireless LAN adapter is inserted to front side USB socket 184,the USB device is made usable.

At step 400, CPU 130 determines whether or not a plug of a USB device isconnected to front side USB socket 184 or to a back side USB socket 186.The USB device may be a USB memory, a USB wireless LAN adapter or thelike. Whether a plug of USB device is inserted to front side USB socket184 or not can be determined, for example, by monitoring electricpotential of a specific terminal (for example, a “+ Data” terminal or “−Data” terminal for data transmission) of front side USB socket 184. Thesame applies to back side USB socket 186. The terminal of USB socket,which has been unconnected and open, has its electric potential changedwhen it is connected to a plug terminal of a USB device. If it isdetermined that a plug of USB device is inserted, the control proceedsto step 402. Otherwise, step 400 is repeated. CPU 130 may monitor theelectric potential of USB socket terminal on a regular basis, or aninterruption to CPU 130 may be caused when the electric potentialchanges.

In the following, it is assumed that a USB wireless LAN adapter 190 isconnected to front side USB socket 184 by an administrator or a serviceperson, as shown in FIG. 5.

At step 402, CPU 130 controls USB host controller 180 and therebyrequests the USB device (USB wireless LAN adapter 190) connected tofront side USB socket 184 for information for specifying the USB device,through USB hub 182. Communication between USB host controller 180 andthe USB device is realized in accordance with known USB standard.Specifically, USB host controller 180 transmits a reset instruction forresetting the inserted USB wireless LAN adapter 190, and thereaftertransmits an instruction (GET_DESCRIPTOR) to get descriptor informationof USB wireless LAN adapter 190. Receiving the instruction, USB wirelessLAN adapter 190 must return the descriptor stored therein, in aprescribed data format without fail.

At step 404, CPU 130 determines whether or not USB host controller 180has received the requested information (descriptor) from the USB device.If it is determined that the information has been received, the controlproceeds to step 406. Otherwise, step 404 is repeated. Before proceedingto step 406, CPU 130 stores the received information in RAM 134.

At step 406, CPU 130 determines whether or not the USB socket to whichthe USB device is inserted is the front side USB socket 184.Specifically, CPU 130 reads a port number at which the use of USB deviceis restricted from HDD 136, and determines whether the port numbermatches that of the USB socket to which insertion of a USB device hasbeen detected at step 400. If the port number of the USB socket to whichinsertion has been detected matches the port number read from HDD 136,it is determined that the device is inserted to front side USB socket184, and the control proceeds to step 408. Otherwise, the controlproceeds to step 418.

At step 408, CPU 130 determines whether the inserted USB device is thedevice of which use is restricted. This can be determined using theclass information (class ID) of USB descriptor.

A USB device has its class ID determined by “USB Implementers Forum,Inc.” in accordance with its function or the like. By way of example,class ID “E0h” (“h” represents that the number is in hexadecimalnotation; same in the following) is allocated to wireless LAN adapter190. Here, the use of USB wireless LAN adapter 190 is restricted.Therefore, as the information for specifying the USB device of which useis restricted, “E0h” is stored beforehand in HDD 136. CPU 130 determineswhether the class ID of descriptor received from the USB device andstored in RAM 134 at step 404 matches “E0h” read from HDD 136. If it isdetermined to be the USB device of which use is restricted (class ID is“E0h”), the control proceeds to step 410. Otherwise (class ID is not“E0h”), the control proceeds to step 418.

At step 418, CPU 130 determines, in order to make the inserted USBusable, whether or not corresponding device driver is stored in HDD 136.If it is determined that the corresponding device driver is stored inHDD 136, the control proceeds to step 420, at which CPU 130 loads thecorresponding device driver, that is, reads the corresponding devicedriver from HDD 136 to RAM 134, and sets the device driver to anexecutable state. Thereafter, the control proceeds to step 416. Thus,the inserted USB device becomes usable in image forming apparatus 100.On the other hand, if it is determined that the corresponding devicedriver is not stored in HDD 136, the control proceeds to step 410. Here,it is assumed that USB wireless LAN adapter 190 is inserted and,therefore, steps 418 and 420 are not executed.

At step 410, CPU 130 displays a prescribed message on operation panel162. When the flow proceeds from step 408 to 410, CPU 130 displays, forexample, a message 500 shown in FIG. 6. FIG. 6 shows message 500,displayed superposed on the operation screen image of image formingapparatus 100 displayed on operation panel 162, indicating that theinserted USB device (USB wireless LAN adapter 190) is not usable throughfront side USB socket 184 but usable through back side USB socket 186.Thus, it is possible for the administrator or service person to pull outthe USB device, that is, USB wireless LAN adapter 190, inserted to frontside USB socket 184 and insert the same to back side USB socket 186.

On the other hand, if the flow proceeds from step 418 to step 410, CPU130 displays, for example, a message 502 shown in FIG. 7. FIG. 7 showsmessage 502, displayed superposed on the operation screen image of imageforming apparatus 100 displayed on operation panel 162, indicating thatthe inserted USB device is unusable, since the device driver of theinserted USB device is not found. Accordingly, it is possible for ageneral user to pull out the USB device inserted to front side USBsocket 184 and, if necessary, to ask the administrator or service personto install the corresponding device driver to image forming apparatus100.

Whether step 410 is executed after step 408 or 418 can be determined bya flag. By way of example, assume that the initial value of the flag is“0”. If it is determined at step 408 that the device is the USB deviceof which use is restricted, CPU 130 sets the flag to “1”. At step 410,CPU 130 displays message 500 such as shown in FIG. 6 if the flag is “1”,and displays message 502 such as shown in FIG. 7 if the flag is “0”.After displaying the message, CPU 130 resets the flag to “0”.

At step 412, CPU 130 determines whether or not the inserted USB devicehas been removed. Whether the USB device is removed or not can bedetermined by detecting the change in electric potential of a prescribedterminal of USB socket. If it is determined that the USB device has beenremoved, the control proceeds to step 414. Otherwise, step 412 isrepeated.

At step 414, CPU 130 erases the message displayed on operation panel162, and displays the original operation screen image.

At step 416, CPU 130 determines whether or not an instruction to end hasbeen received. If it is determined that the end instruction is received,the program ends. Otherwise, the control returns to step 400. The endinstruction is given, for example, when the power of image formingapparatus 100 is turned off.

In the above-described manner, if USB wireless LAN adapter 190 isinserted to front side USB socket 184 and the corresponding devicedriver is stored in HDD 136, USB wireless LAN adapter 190 is not set toa usable state since steps 400 to 410 are executed, and a message tothat effect is displayed on operation panel 162. Viewing the message,the administrator or service person removes USB wireless LAN adapter 190from front side USB socket 184 and inserts it to back side USB socket186. Thereafter, steps 400 to 406 and steps 418 to 420 are executed, sothat USB wireless LAN adapter 190 becomes usable. Since USB wireless LANadapter 190 is used inserted to back side USB socket 186 that is noteasily accessible, even though it is used in the constantly connectedstate, possibility of any damage or erroneous removal is low.

When a general user inserts a USB device (for example, a USB memory)other than USB wireless LAN adapter 190 to front side USB socket 184, atstep 408, it is determined to be a USB device of which use is notrestricted and, therefore, the device is made usable.

Though an example in which class information is used for specifying theUSB device of which use is restricted has been described above, it isnot limiting. By way of example, vender ID and product ID in thedescriptor may be used. In that case, at step 408, CPU 130 may determinewhether or not the vender ID and the product ID (which are stored in RAM134 at step 404) of the descriptor received from the USB device matchthe vendor ID and the product ID (information for specifying the USBdevice of which use is restricted) stored beforehand in HDD 136.

Vender ID represents information for specifying the manufacturer of theUSB device, and product ID represents information for specifying theproduct of the manufacturer. The product ID is designated by themanufacturer of the USB device, while the vendor ID is determined uponapplication by the manufacturer to “USB Implementers Forum, Inc.” Thevendor IDs are publicly known and data corresponding to themanufacturers are available at the web page of “USB Implementers Forum,Inc.” (http://www.usb.org).

Though an example in which the USB device of which use is restricted isa USB wireless LAN adapter has been described above, it is not limiting.It may be any USB-connectable device that expands the function of imageforming apparatus, and it may be an external storage device (HDD or thelike) or a user authentication apparatus (IC card reader, magnetic cardreader, or fingerprint authentication device) or the like. If such adevice is used constantly connected to the front side USB socket,possibility of damage or erroneous removal is high. Therefore, it isdesirable to make the device unusable when it is connected to the frontside USB socket.

FIG. 8 shows examples of class ID. For instance, the class ID of an ICcard reader is “0Bh”. Therefore, when an IC card reader is connected toan image forming apparatus to be used for user authentication using anIC card, “0Bh” should be stored beforehand in HDD 136 as the informationfor specifying the USB device of which use is restricted, so that the ICcard reader is not connected to the front side USB socket. If afingerprint reader is connected for user authentication, “0Dh” should bestored beforehand in HDD 136 as the information for specifying the USBdevice of which use is restricted. If use of two or more USB devices isto be restricted, class IDs of these devices may be stored in advance inHDD 136.

It is noted that the class ID of an external storage device such as anexternal HDD is “08h”, which is the same as that of a USB memory.Therefore, it is impossible to distinguish them only by the class ID. Itis possible, however, to restrict use of an external storage device byusing vendor ID and product ID.

Though an image forming apparatus having USB sockets on the front andback sides has been describe above, it is not limiting. The presentinvention is applicable to any image forming apparatus that has a USBsocket at a position where the user can manually insert and remove theUSB device (for example, front side) and a USB socket at a positionwhere the user cannot manually insert and remove the USB device (forexample, on a side other than the front side), when the user stands nearthe operation unit for operating the image forming apparatus. By way ofexample, if the image forming apparatus has USB sockets on the frontside and on the deep position on the right side, the USB socket 188 onthe side surface may be handled in the same manner as back side USBsocket 186 described above.

Though an example in which the device driver is automatically loaded andthe USB device is made usable at step 420 has been described above, ascreen image allowing input of necessary settings may be displayed onoperation panel 162. By way of example, if it is a USB wireless LANadapter, it is possible to have the device driver loaded and toautomatically detect and connect to a wireless router or an access pointnearby. If a plurality of connectable wireless routers or access pointsare detected at that time, the detected plurality of connectiondestinations may be displayed on operation panel 162, allowing selectionby the user. Alternatively, after the device driver is loaded, a screenimage allowing input of an IP address of the connection destination maybe displayed. Further, known security of wireless communication such asWEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access) or the likemay be set.

The embodiments as have been described here are mere examples and shouldnot be interpreted as restrictive. The scope of the present invention isdetermined by each of the claims with appropriate consideration of thewritten description of the embodiments and embraces modifications withinthe meaning of, and equivalent to, the languages in the claims.

INDUSTRIAL APPLICABILITY

By the present invention, an image forming apparatus capable of reducingthe possibility of a USB-connected function enhancement device such as aUSB wireless LAN adapter being damaged by an external force and thepossibility of such a device being erroneously removed can be provided.

DESCRIPTION OF THE REFERENCE SIGNS

-   -   100 image forming apparatus    -   110 body    -   120 automatic document feeder    -   130 control unit (CPU)    -   132 ROM    -   134 RAM    -   136 HDD    -   140 image reading unit (scanner unit)    -   142 bus    -   150 image forming unit    -   152 image processing unit    -   154 image memory    -   156 paper feed unit    -   160 operating unit    -   162 operation panel    -   170 in-barrel type paper discharge tray    -   180 USB host controller    -   182 USB hub    -   184 front side USB socket    -   186 back side USB socket    -   190 USB wireless LAN adapter

The invention claimed is:
 1. An image forming apparatus provided with aplurality of USB sockets, wherein: a type of device usable with each ofsaid plurality of USB sockets is set; said apparatus comprising: acontrol unit for selectively executing a process of making, in mutuallydifferent manners, usable or unusable a device connected to a prescribedone of said plurality of USB sockets and a device connected to a USBsocket different from said prescribed one of said plurality of USBsockets, wherein the type set for said prescribed USB socket among saidplurality of USB sockets is different from the type set for a USB socketdifferent from said prescribed USB socket.
 2. The image formingapparatus according to claim 1, wherein said device is a USB deviceconnected to said USB socket is a USB memory or a USB device forcommunication with external equipment.
 3. The image forming apparatusaccording to claim 1, further comprising an operation unit receiving aninstruction to said image forming apparatus; wherein said prescribed USBsocket is arranged on a front side of said image forming apparatus wheresaid operation unit is arranged; and each of said plurality of USBsockets different from said prescribed USB socket is arranged on a sideother than said front side of said image forming apparatus.
 4. The imageforming apparatus according to claim 3, wherein each of said pluralityof USB sockets different from said prescribed USB socket is arranged ona back side opposite to said front side of said image forming apparatus.5. The image forming apparatus according to claim 1, wherein saidcontrol unit determines whether or not the USB device connected to saidprescribed USB socket is to be made usable, by obtaining classinformation of the USB device from the USB device connected to saidprescribed USB socket and determining whether or not said obtained classinformation is prescribed class information.
 6. The image formingapparatus according to claim 1, wherein said control unit determineswhether or not the USB device connected to said prescribed USB socket isto be made usable, by obtaining a vendor ID and a product ID of the USBdevice from the USB device connected to said prescribed USB socket anddetermining whether the obtained vendor ID and the obtained product IDare a prescribed vendor ID and a prescribed product ID.
 7. The imageforming apparatus according to claim 1, further comprising a displayunit for displaying information; wherein the process of said controlunit keeping unusable said USB device includes a process of displayinginformation that said USB device is unusable on said display unit.